ECOWILL compact household cogeneration unit

A home gas cogeneration system is a high-efficiency, environmentally responsible heat/electricity supply system that generates electricity with a gas engine and utilizes the exhaust heat to provide hot water. Before Honda’s innovations, cogeneration systems had been implemented only in factories, hospitals and other large-scale buildings. Honda developed the world’s first cogeneration system for household use by leveraging the compact generator and engine technologies that it had been developing since its foundation.

In March 2003, Honda launched the ECOWILL compact household cogeneration unit, which combined the GE160V, the world’s smallest gas engine, with Honda’s original sine wave inverter technology. In October 2006, Honda introduced a new quieter and more compact ECOWILL model that raised power generation efficiency to 22.5% and combined power and heat generation efficiency to 85.5%. Reducing CO₂ emissions by 30% versus the conventional method of generating heat and electricity separately, ECOWILL became a popular way for households to reduce their energy consumption and, as of December 2008, was in use in 80,000 households in Japan.

In March 2007, Honda and Boston-based Climate Energy, LLC jointly began retail sales of the freewatt™ household cogeneration system in Massachusetts, since then expanding sales to Rhode Island and New York.